What would happen if i drank someone else's blood?

Answer 1

that is the leading cause of muscle spasm disficiation, this is where the muscles spasms and "leaps" out of the body and in a attempt to remove all the blood from the body consumed by the other person. Usually starts with headaches and stomach cramps

A different answer:

First, I can't find a definition for the word "disficiation", so I can't address the medical basis involved. Second, drinking human blood is most certainly not the leading cause of muscle spasms in humans (or any other animal I've ever heard of). If I had to pick a cause in healthy individuals, I'd go with electrolyte depletion/imbalance.

Gastrointestinal bleeds do indeed often induce vomiting, and so do esophageal bleeds (to a lesser extent). So drinking someone else's blood might as well induce vomiting.

Headaches do not figure into this matter at all.

Drinking human blood is a risky business for humans, however. Humans harbor parasites and pathogens that attack humans effective, and resist human immunological systems. So drinking human blood exposes the drinker to these dangers. A bad idea altogether.